Sorry to hear about the damage. Suction cup failure is one of those issues all of us large 'glass' tank guys sweat more than any other aspect of the tank move ...
As far as the glass conservation factor goes, you're likely better off just buying new glass if you were to go about reconstruction. Being that the 140G is older, it was more than likely constructed using regular float glass. Therefore, it wouldnt be worth much used unless it truly is very thick i.e. 15mm; 19mm + ... You'd have to look into replacement prices for the sizing/thickness of that glass, but again I imagine it wouldn't be worth your efforts to salvage it. Again, unless it is 15; 19mm +, as you would also need to factor in the cost/time of stripping the old silicone, etc at that point.